Isner, Verdasco win Houston openers

John Isner and Fernando Verdasco highlighted Tuesday's first-round winners during Day Two of the $455,000 U.S. Men's Clay Court Championship.

The fifth-seeded Isner, the runner-up to gritty Argentine Juan Monaco in this event last year, prevailed in a first-set tiebreaker en route to a 7-6 (7-4), 6-4 decision over fellow American Ryan Harrison at River Oaks Country Club.

Verdasco also had to withstand an opening-set challenge in his match with Steve Johnson before taking down the American wild card by a 7-6 (7-5), 6-2 score.

Johnson was a two-time NCAA champion at the University of Southern California.

Isner's next opponent will be Jack Sock after the wild-card entry stopped qualifier and fellow American Bradley Klahn 7-6 (7-3), 6-3

This week's top seeds are Spanish star Nicolas Almagro, resurgent German Tommy Haas and the reigning champion Monaco. The former world No. 2 Haas captured this event in 2004 and will meet Berankis in his opener this week.